https://cdn.form.io/formiojs/versions.json not up to date

[Rolf]

Describe the bug
Using online sandbox https://formio.github.io/formio.js/app/sandbox the selectable formio versions is not complete.

Not sure if the switching between versions is working (as intended).

At the time of writing e.g. https://cdn.form.io/formiojs/4.19.0/formio.form.css exists but 4.19.0 is not listed in the available formio.js versions select box.

The versions info is pulled from: https://cdn.form.io/formiojs/versions.json

Version/Branch
Latest online https://formio.github.io/formio.js/app/sandbox

To Reproduce
Steps to reproduce the behavior:
See above.

Expected behavior
Up to date sandbox - switching between versions to be working.
Would be nice to be able to only see releases and hide RCs.

Screenshots
N/A

Additional context
N/A